1 | """ |
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2 | ASCII 2D Loader |
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3 | """ |
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4 | from sas.sascalc.dataloader.data_info import Data2D |
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5 | from sas.sascalc.file_converter.nxcansas_writer import NXcanSASWriter |
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6 | import numpy as np |
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7 | |
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8 | # ISIS 2D ASCII File Format |
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9 | # line: property |
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10 | # 0: File header |
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11 | # 1: q_x axis label and units |
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12 | # 2: q_y axis label and units |
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13 | # 3: Intensity axis label and units |
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14 | # 4: nUseRec - number of lines of user content following this line |
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15 | # 5 - 5+nUseRec: user content |
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16 | # Number of qx points |
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17 | # List of qx points |
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18 | # Number of qy points |
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19 | # List of qy points |
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20 | # numqx numqy scale |
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21 | |
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22 | class ASCII2DLoader(object): |
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23 | |
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24 | def __init__(self, data_path): |
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25 | self.data_path = data_path |
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26 | |
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27 | def load(self): |
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28 | file_handle = open(self.data_path, 'r') |
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29 | file_buffer = file_handle.read() |
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30 | all_lines = file_buffer.splitlines() |
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31 | |
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32 | def _load_qs(lines, start_line, num_points): |
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33 | qs = np.zeros(num_points) |
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34 | n = start_line |
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35 | filled = 0 |
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36 | while filled < num_points: |
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37 | row = np.fromstring(lines[n], dtype=np.float32, sep=' ') |
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38 | qs[filled:filled+len(row)] = row |
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39 | filled += len(row) |
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40 | n += 1 |
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41 | return n, qs |
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42 | |
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43 | # Skip nUseRec lines |
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44 | current_line = 4 |
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45 | nUseRec = int(all_lines[current_line].strip()[0]) |
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46 | current_line += nUseRec + 1 |
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47 | |
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48 | # Read qx data |
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49 | num_qs = int(all_lines[current_line].strip()) |
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50 | current_line += 1 |
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51 | current_line, qx = _load_qs(all_lines, current_line, num_qs) |
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52 | |
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53 | # Read qy data |
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54 | num_qs = int(all_lines[current_line].strip()) |
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55 | current_line += 1 |
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56 | current_line, qy = _load_qs(all_lines, current_line, num_qs) |
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57 | |
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58 | # dimensions: [width, height, scale] |
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59 | dimensions = np.fromstring(all_lines[current_line], dtype=np.float32, sep=' ') |
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60 | width = int(dimensions[0]) |
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61 | height = int(dimensions[1]) |
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62 | |
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63 | # More qx and/or qy points can be provided than are actually used |
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64 | qx = qx[:width] |
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65 | qy = qy[:height] |
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66 | |
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67 | current_line += 1 |
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68 | # iflag = 1 => Only intensity data (not dealt with here) |
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69 | # iflag = 2 => q axis and intensity data |
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70 | # iflag = 3 => q axis, intensity and error data |
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71 | iflag = int(all_lines[current_line].strip()[0]) |
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72 | current_line += 1 |
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73 | |
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74 | current_line, I = _load_qs(all_lines, current_line, width*height) |
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75 | dI = np.zeros(width*height) |
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76 | |
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77 | if iflag == 3: |
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78 | _, dI = _load_qs(all_lines, current_line, width*height) |
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79 | |
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80 | # Format data for use with Data2D |
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81 | qx = list(qx) * height |
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82 | qy = np.array([[y] * width for y in qy]).flatten() |
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83 | |
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84 | data = Data2D(qx_data=qx, qy_data=qy, data=I, err_data=dI) |
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85 | |
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86 | return data |
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